9
Regardless of the type of transducer or
meter employed, the 1040C has a provision
for direct calibration of power factor. As
stated earlier in this document, the power
factor in a circuit is equal to the cosine of the
phase angle between the voltage and the
current. With this in mind, any power factor
can be simulated by adjusting the phase
relationship between the voltage and current,
which can be accomplished quite easily with
the 1040C. Two methods can be used:
•
The required phase angle can be entered
directly via the keypad, as described in
the section on phase angle calibration;
•
The power factor can be entered directly,
by first pressing the "Power Factor" key,
then using the adjust knob to vary the
displayed power factor. This method
allows entry of lead or lag power factor
values without having to first calculate
the corresponding phase angle.
Calibration of the transducer should be
performed according to the instrument
manufacturer's recom-mendations.
Typical applications of power factor
meters
for multi-phase systems involve
circuit connections which are similar, if not
identical to those employed by multi-phase
phase angle transducers. Generally, the
current is measured in one phase, and a
comparison is made between it and the net
voltage between the remaining two phases.
Substituting a meter for the transducers
shown in figure 11 will give a good
indication of the type of connections
necessary for typical applications and
calibration.
For more detailed instructions on
operating the 1040C for calibration of power
factor, refer to section 2.5.1 of the operation
manual.
